Method and control apparatus for controlling a lighting module based on a constant current level from a power source are disclosed. The control apparatus may be operable: to determine an indication of a constant current level of the power source; to determine an activation ratio in which to activate first and second groups of LEDs each cycle period based upon the indication of the constant current level; and to selectively couple the first and second groups of LEDs to the power source each cycle period based upon the first activation ratio. The first and second groups of LEDs may comprise LEDs of first and second color temperatures respectively. The control apparatus can be adapted to operate as a dim-to-warm module within a lighting apparatus.